The goal of research conducted since 6/01/76 has been to determine the ability of dichromatic absorptiometry to measure physiologic changes in soft tissue fluid. Changes in soft tissue fluid measured by dichromatic absorptiometry correlated with experimentally produced changes in total body water in dogs (correlation coefficient r equals 0.96). Similarly, changes in upper limb soft tissue fluid measured by dichromatic absorptiometry correlated with changes in total bodywater in surgical patients (correlation coefficient r equals 0.74). Dichromatic absorptiometry has been found to be useful in studying changes in the distribution of body water and is being used to study the effect of various therapies on accumulation and resolution of burn edema. During the next grant period, dichromatic absorptiometry will be used to measure central and peripheral fluid distribution in experimental animals and in patients.